1. Field of the Invention
The present invention relates in general to a recovery device for extracting liquids and vapor from subterranean strata and more specifically relates to a fuel recovery device activated by compressed fluid.
2. Description of the Prior Art
Large numbers of underground fuel storage tanks were buried in position during the 1950's as part of many new automobile service stations opened to accommodate increasing vehicular traffic traveling the nation's roadways. The physical condition of many of the storage tanks installed at that time has substantially deteriorated and leaky tanks are becoming a not uncommon problem for service station owners.
When a leak occurs in an underground storage tank escaped fuel generally diffuses away from the high pressure of the tank and settles downward until it is trapped in substrata of the surrounding terrain or else reaches the water table of such terrain, whereupon it collects as a layer on top of the saturated soil of the water table. Such accumulation of fuel contaminates the water table and poses a serious hazard to both the service station of which the tank is a part and to the public in general. This hazard to the owner of the service station is accentuated by the fact that there is presently no insurance offered that will protect an owner in the event of a tank leak, and prior methods for recovering escaped fuel are unreasonably expensive.
The most common method in present use for recovering escaped fuel is the drilling of a standard well shaft down to the water table and then pumping out of the ground escaped fuel that collects in the shaft. Of course, such method must depend on the voluntary drainage of fuel into the well shaft and generally results in a long and taxing operation. Furthermore, the percentage of fuel recovered by this prior art method is relatively low and such recovery does little about vaporized fuel that may have permeated the terrain. Accordingly, an urgent need exists for a rapid and efficient fuel recovery device that will recover not only escaped fuel in liquid form but also vaporized fuel.